Mars is the fourth planet away from the Sun and
is about half the size of our planet Earth.
For many years, we used to think there might be
life on Mars.
This came from astronomers who looked at the planet
through really simple telescopes. They thought they could see dark
lines all over the surface of the planet.
This made them think that the dark lines were actually
huge alien-made rivers to carry water from the frozen north and
south pole of the planet to the drier areas.
But since then, we have found that the telescopes
they were using were so bad that the lines really weren't there
and were just a trick of the eye.
Volcano Olympus Mons on Mars
We are now sure there is no intelligent life on
Mars, but who knows, there may be really simple forms of life, maybe
even simpler than the bacteria on the Earth.
Maybe one day, one of you will be the scientist
who discovers life on Mars or somewhere else in space!
Why is Mars red?
Mars is red because it's covered in something
called iron oxide. This is the proper name for rust. If you leave
any metal object outside in the rain, the iron in the metal and
the oxygen in the rain water join up to make iron oxide which we
know as rust.
The surface of Mars is covered in the same sort
of material giving it its red colour.
One other really amazing thing about Mars is that
it's got the biggest known volcano in the Solar System.
This volcano is called Olympus Mons. It's so big
that it would tower above the biggest volcanoes on the Earth.
It hasn't erupted for many thousands of years but
if it ever does erupt we'll get a fantastic view from the Earth.
Got a question about Mars? Ask
our astronomy expert, Mark »